The present invention relates to a process cartridge and an electrophotographic image forming apparatus.
Here, an electrophotographic image forming apparatus is an apparatus which forms an image on a recording medium with the use of an electrophotographic image formation method. As examples of an image forming apparatus, there are an electrophotographic copying machine, an electrophotographic printer (for example, a laser printer, an LED printer, and the like), a facsimile machine, a word processor, and the like.
A process cartridge is a cartridge which integrally comprises a charging means, a developing means or a cleaning means, and an electrophotographic photosensitive drum, and is removably mountable in the main assembly of an electrophotographic image forming apparatus. It also is a cartridge which integrally comprises a minimum of one means among a charging means, a developing means, and cleaning means, and an electrophotographic photosensitive drum, and is removably mountable in the main assembly of an electrophotographic image forming apparatus, and a cartridge which integrally comprises a minimum of a developing means, and an electrophotographic photosensitive drum, and is removably mountable in the main assembly of an electrophotographic image forming apparatus.
A process cartridge system is employed by an electrophotographic image forming apparatus which employs an electrophotographic formation process. According to a process cartridge system, an electrophotographic photosensitive member, and a single or a plurality of processing means, which act on the electrophotographic photosensitive member, are integrated in the form of a cartridge removably mountable in the main assembly of an image forming apparatus. A process cartridge system makes it possible for a user to maintain an electrophotographic image forming apparatus without relying on service personnel, remarkably improving the operational efficiency of an electrophotographic image forming apparatus. Therefore, a process cartridge system is widely used in the field of an electrophotographic image forming apparatus.
Referring to FIG. 33, a conventional process cartridge 85 comprises a development unit and a cleaning unit, which are joined with each other with the use of connecting pins 89. The development unit comprises a developing means container 83 and a toner container 86, which are welded to each other by ultrasonic welding. The developing means container 83 supports a development roller 18. The cleaning unit comprises a photosensitive drum 11, a charge roller 12, a cleaning blade 14, a cleaning means container 87, and the like. The photosensitive drum 11, the charge roller 12, the cleaning blade 14, and the like, are supported by the cleaning means container 87. Further, a pair of compression springs 82 are placed in a compressed state between the cleaning means container 87 and developing means container 83, keeping the photosensitive drum 11 and development roller 18 pressed toward each other.
In the case of an electrophotographic image forming apparatus employing a process cartridge such as the one described above, there is a tendency that in order to extend the process cartridge replacement interval, in other words, in order to extend the length of the service life of a process cartridge, a toner container (developer container) and a cleaning means container are increased in capacity.
The present invention is the result of the further development of the prior art. The primary object of the present invention is to provide a process cartridge and an electrophotographic image forming apparatus, which ensure that a driving force is reliably transmitted from the main assembly of the image forming apparatus to the process cartridge.
Another object of the present invention is to provide a process cartridge and an electrophotographic image forming apparatus, which ensure that the process cartridge reliably receives the driving force for driving an electrophotographic photosensitive member and a developer sending member.
Another object of the present invention is to provide a process cartridge and an electrophotographic image forming apparatus, which ensure that a developer sending member is reliably driven.
According to an aspect of the present invention, there is provided a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus. The process cartridge includes an electrophotographic photosensitive member; a developing member for developing an electrostatic latent image formed on the electrophotographic photosensitive member; a developer accommodating portion for accommodating a developer to be used for development of the electrostatic latent image by the developing member, a developer discharging member for discharging the developer accommodated in the developer accommodating portion toward the developing member; a cartridge positioning portion for engagement with a main assembly positioning portion provided in the main assembly of the apparatus when the process cartridge is mounted to the main assembly of the apparatus, the cartridge positioning portion being disposed at a developer accommodating portion side in a direction crossing with a direction of an axis of the electrophotographic photosensitive member; a photosensitive member driving force receiving portion for receiving a driving force for rotating the electrophotographic photosensitive member from the main assembly of the apparatus when the process cartridge is mounted to the main assembly of the apparatus, the photosensitive member driving force receiving portion being disposed at a leading side with respect to a direction of mounting the process cartridge to the main assembly of the apparatus, wherein the process cartridge is mounted to the main assembly of the apparatus in the direction of the axis of the electrophotographic photosensitive member; and a discharging member driving force receiving portion for receiving a driving force for rotating the developer discharging member from the main assembly of the apparatus when the process cartridge is mounted to the main assembly of the apparatus. The rotational directions of the photosensitive member driving force receiving portion and the discharging member driving force receiving portion when the photosensitive member driving force receiving portion and the discharging member driving force receiving portion receive driving forces from the main assembly of the apparatus, are the same, and the rotation of directions are such that a rotation moment is produced so as to contact the cartridge positioning portion to a lower surface of the main assembly positioning portion of the apparatus.
According to a further aspect of the present invention, there is provided a process cartridge and an electrophotographic image forming apparatus, which are characterized in that the process cartridge is mounted into an apparatus main assembly in a direction cartridge comprises: a cartridge positioning portion which is located on the same side as the developer storing portion, in terms of the direction perpendicular to the axial direction of the electrophotographic photosensitive member, and engages with the cartridge positioning portion of the main assembly of the image forming apparatus; a photosensitive member driving force receiving portion, which is for receiving the driving force for driving the electrophotographic photosensitive member, from the apparatus main assembly, when the process cartridge is in the proper position in the apparatus main assembly, and which is located at the leading end of the process cartridge, in terms of the direction in which the process cartridge is mounted into the apparatus main assembly; and a developer sending member driving force receiving portion, which is for receiving the driving force for rotating the developer sending member, from the apparatus main assembly, and which is located at the leading end of the process cartridge in terms of the direction in which the process cartridge is mounted into the apparatus main assembly.
Another object of the present invention is to provide a process cartridge having a toner discharging or sending member which ensures that even if the process cartridge is substantially increased in toner capacity, compared to a conventional process cartridge, images of satisfactory quality are always formed, and also to provide an electrophotographic image forming apparatus compatible with such a process cartridge.
These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.